Ch.13 vocab Flashcards
an extremely thin, less dense solid covering over the mantle
crust
a layer that makes up the majority of the earth and surrounds a small core of iron
mantle
made up of the crust and outer mantle
lithosphere
layer just below the outer mantle that is capable of flow
athenosphere
concept that the outer layer of the earth consists of large plates composed of outer portion of the mantle
plate tectonics
the breakdown of parent material into smaller particles that will become soil
weathering
results from physical forces that reduce the size of rock particles, changes in temperature, wind, rain, snow, and moving water will cause this
mechanical weathering
chemical alteration of rocks causing them to oxidize and break down over time
chemical weathering
process of loosening and redistributing particles of soil over the landscape
erosion
a thin covering over the land consisting of a mixture of minerals, organic material, air, water, and organisms
soil
part of the world not covered by ocean
land
ancient layers of rock often from mountains and hills
parent material
organic material from the decay of dead plant and animal material
humus
particles between .05 and 2.0 mm in size
sand
particles less than .002 mm in diameter
clay
ideal soil for agricultural use, a specific combination, of sand, silt, and clay
loam
the various ways that soil particles clump together, how they stick to one another
soil structure
soil structure determined by soil structure and moisture content, crumbles easily
friable
series of horizontal layers in the soil that differ in chemical composition and physical properties
soil profile
each recognizable layer of soil that differs in composition is identified
horizon
undecomposed or somewhat decomposed organic matter found on the ground of forests
litter
water moving down through the soil and carrying with it organic materials and minerals
leaching
tilling the land at right angles to the slope in order to prevent erosion
contour farming
the planting of different crops in strips to reduce erosion and produce a variety of crops
strip farming
level areas constructed on a hillside to increase land usable for farming
terraces
low lying ground that collects water as it flows downhill, streams and rivers
waterways
planting of trees that protect bare soil from the full force of the wind
windbreaks
a tillage method that usually leaves 15 to 30 percent of the land covered with crop residue
reduced tillage
increases the amount of surface covered by crop residue to up to 50 percent
conservation tillage
